Super73Nova

I seriously thought it was rod knock on several because of how loud it was. My manger insisted I pull the engine and tear it down on one of the first ones because of how loud it was. Since the noise went away after a very brief warm up I told him it probably wasn’t a rod but he was the manager and knows more than anyone else . I wouldn’t persue it at the dealer. Like you said a new shortblock going in could just cause more problems than it’s worth. I didn’t want to believe it was piston slap at first but it definitely is. Not sure what the pistons are made out of but it reminds me of how a forged piston acts.

This is a normal cold characteristic of these engines. It’s piston slap and after some heat gets in the piston is goes away. I’ve torn down engines on a few of your body style because it was pretty loud only to find nothing wrong. Some can get pretty noisy but like every Subaru pretty much, it’s normal!